Hypertension and renal disease: role of microalbuminuria

RISKS ASSOCIATED WITH HYPERTENSION: Hypertension is a risk factor for cardiovascular and possibly renal organ damage. Microalbuminuria is a newly recognized cardiovascular and renal risk factor in diabetic and non-diabetic subjects. The prevalence of microalbuminuria is enhanced in hypertensive subjects, in particular in those with blood pressure characteristics that are associated with enhanced cardiovascular risk, such as salt-sensitivity and an abnormal diurnal blood pressure rhythm.

Although microalbuminuria is more prevalent in hypertensives and is shown to be a strong and independent risk factor, the relation between microalbuminuria and hypertensive complications is unknown. Even more intriguing is the finding of elevated levels of microalbuminuria in normotensive children with one or two parents with hypertension. This suggests that microalbuminuria is linked to the pathogenesis of hypertension. However, the role and the cause(s) of microalbuminuria are uncertain. Microalbuminuria seems to link renal and cardiovascular organ damage. Microalbuminuria might be the consequence of (renal) organ damage induced by hypertension. Alternatively, microalbuminuria might be an independent marker of some process that occurs separately from diabetes, hypertension or dyslipidemia. Endothelial dysfunction has been suggested to underlie renal and/or cardiovascular organ damage in these diseases. More knowledge should be obtained on the cause and the natural course of microalbuminuria.

Microalbuminuria possibly identifies at an early stage hypertensive patients with an enhanced risk of developing the well-known renal and cardiovascular hypertensive complications. For the patients at particular risk therapeutic measures than can be developed. If microalbuminuria identifies a specific underlying pathogenetic mechanism, these measures may intervene with such a mechanism. Alternatively, if microalbuminuria identifies enhanced risk then standard antihypertensive therapy can be intensified, since such measures also lower microalbuminuria.